


The unfathomable cruelty that is chemistry

by jonathanegbert



Category: Haikyuu!!
Genre: Chemistry, In which Hinata and Kageyama are dumbasses
Language: English
Status: Completed
Published: 2020-05-30
Updated: 2020-05-30
Packaged: 2021-03-03 05:36:02
Rating: General Audiences
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 1
Words: 3,052
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/24449716
Author URL: https://archiveofourown.org/users/jonathanegbert/pseuds/jonathanegbert
Summary: “Stupid Kageyama, move out of the way, you’re doing it wrong!” Fumbling could be heard in Hinata’s room. Sounds of glass clinking and yelps as things almost spill and break resound.“Oi, Hinata, you’ll break the beakers! Give that to me.” Muffled yells sound through the walls and there’s a loud thump as bodies hit the floor, a collective “oof!” rising from the two boys fighting.Natsu turns her head to the sounds coming from down the hallway, pausing in her coloring as her brows furrow together.The girl gets up and pads down the hall to her brother’s room, interrupting some shouting when she knocks shyly on the door. A stifled “come in!” is heard and Natsu turns the knob, the door opening to reveal a tangle of two boys as Kageyama holds a beaker away from Hinata above his shorter head and Hinata attempts to climb him. The two pause.“Oh, hey Natsu!”
Comments: 5
Kudos: 11





	The unfathomable cruelty that is chemistry

**Author's Note:**

  * Inspired by [The Unfathomable Cruelty that is Chemistry](https://archiveofourown.org/works/5638186) by [jonathanegbert](https://archiveofourown.org/users/jonathanegbert/pseuds/jonathanegbert). 



> Updated, extended, and reposted for an application to a zine!

“Stupid Kageyama, move out of the way, you’re doing it wrong!” Fumbling could be heard in Hinata’s room. Sounds of glass clinking and yelps as things almost spill and break resound.

“Oi, Hinata, you’ll break the beakers! Give that to me.” Muffled yells sound through the walls and there’s a loud thump as bodies hit the floor, a collective “oof!” rising from the two boys fighting.

Natsu turns her head to the sounds coming from down the hallway, pausing in her coloring as her brows furrow together.

The girl gets up and pads down the hall to her brother’s room, interrupting some shouting when she knocks shyly on the door. A stifled “come in!” is heard and Natsu turns the knob, the door opening to reveal a tangle of two boys as Kageyama holds a beaker away from Hinata above his shorter head and Hinata attempts to climb him. The two pause.

“Oh, hey Natsu!” says Hinata a little breathless from physical strain, turning to her and temporarily backing away from the fight. “Did you need something?”

“U-um,” Natsu’s cheeks darken under the gaze of Kageyama and she averts her eyes elsewhere. Hinata resists the laugh that he wants to give; his little sister was shy, and Kageyama was tall and angry-looking and scary. “You guys are loud so I wanted to know what you were doing!”

“Oh.” Hinata looks back to Kageyama and frowns, remembering what had been happening before Natsu’s arrival. “We’re trying to do a thing for school but Kageyama is being stupid because he doesn’t actually know how to do it!” His sentence more directed towards Kageyama than Natsu.

Kageyama’s face goes red. “O-oi!” He grips his beaker in one hand and forms a fist with the other, widening his stance defensively. “With the clumsy way you’re always doing things, you’re going to break all our borrowed materials, idiot!” Hinata fumes, blushing in rage.

He raises a finger to poke into Kageyama’s face, but before he can retaliate, Natsu inquires, “Materials for what?” Hinata turns back to Natsu, a little irritated.

“Chemistry lab.”

The little girl sounds out the word herself. “Chemis...try?”

“Yeah,” says Hinata, “science.”

feet. “Oh! In class I was learning about how water, um, rains down from the clouds, and then how when it falls into the oceans, the sun shines on them and the water eva- evaperates!”

Kageyama, being the awkward giant he is with children, simply asks, “Evaporates?”

Natsu nods enthusiastically.

Hinata glances at Kageyama and gapes, moving his hand to cover Kageyama’s face. “Don’t make that face, you look scary! You’ll make my sister cry!”

Kageyama knocks Hinata’s hand off his eyes, “This is my normal face, dumb-- idiot!” He catches his language, remembering Natsu is right there. 

“Get a new one!”

“Your face sucks more!” Kageyama retorts, grabbing at Hinata’s face and smushing his cheeks together. Hinata flails. 

The pair hears a huff from where Natsu is standing, and when they turn to her she’s crossed her arms, looking childishly stern.

Kageyama releases Hinata’s face, which forms a smile. “Sorry, Natsu. But yeah! It’s something like that. Evaporation and all. Could you let us get back to our lab, now?”

“Idiot, our thing is nothing like that,” Kageyama says. Natsu’s eyes widen in curiosity.

“What’s it like?” Asks Natsu, leaning towards the taller boys, eyes burning with unasked questions.

“How the heck do you explain heat and enthalpy to a little kid?” Kageyama asks, raising an eyebrow at Hinata. Hinata shrugs, an “I’unno” following.

“Oh, oh! Heat is how hot something is, right!” Natsu’s arm is raised as if to answer a question in class.

Hinata sees Kageyama’s intense gaze and turns to his younger sister. “Natsu, I’m so sorry for what you’re about to hear.” Hinata feels pity for Natsu, only a child, too young to bear the cruel, unfathomable burden of chemistry. 

Kageyama stands up straight and squares his shoulders, staring straight ahead fiercely as he recites what he studied so hard to memorize. “Heat is the transfer of energy from one hotter system to another cooler system.”

Natsu is taken aback and her mouth drops.

She’s about to go off like a bullet, shooting a thousand questions a minute, but Hinata puts a hand on her shoulder and is able to placate her just in time, telling her, “Relax, it’s nothing you have to know, yet.”

Deciding to take the opportunity he has here, though, Hinata spins around to Kageyama, shooting a question as he points a finger in his direction: “Kageyama, what is energy?!”

Kageyama straightens up stiffly, hands at his sides as if he were in the military. “The ability to do work!” He yells confidently.

“And what is the difference between heat and energy, Kageyama!”

Kageyama falters a little, stuttering, but soon gets back into momentum, “Energy is the general umbrella term encompassing things that catalyze reactions, like heat. Heat is a form of energy and it is kinetic energy, meaning energy in motion!”

Hinata laughs, “Nice, Kageyama! I just wanted to test you, I didn’t even know the answer to that last one myself–”

A vein pulses in Kageyama’s forehead, “–Why did you ask, then–”

“But you’ve been studying a lot so we can travel to Tokyo, huh? Good work!” Hinata claps Kageyama’s back and Kageyama stumbles forward with the force of it. The vein in his forehead continues to pulse.

“Why are we friends–” The taller boy wonders aloud.

Hinata laughs again, “Ok, onto the lab!”

Natsu, who the two had forgotten was there, suddenly bursts out, “Can I watch?”

“Natsu, we really need to concentrate on this–“

“–Pleaaase?”

“Fine,” Hinata relents. Natsu nods furiously, eyes shining at being able to witness some miraculous phenomenon she could understand nothing of.

Kageyama looks around the room. “Alright, let’s gather the equipment.”

Hinata bends down, picking up some items scattered on the floor and putting it on the desk.

“Okay, so we have the two beakers, the dumb calorimeter you made which could’ve been done a lot better in my opinion–”

“Oi!”

“–look, all sorts of things could go wrong with it! The top doesn’t screw as tight and I’m not even sure if this is the right material! There’s so much chance of us losing heat in this. Anyway, we have a balance, aaaand… the thermometers!”

Natsu is entranced as the boys bound around, measuring the masses of the two beakers, filling one with tap water and filling the other with water they heated, then measuring the masses again.

“Kageyama,” calls Hinata, “measure the temperatures of the water as I record the masses.”

"Don't tell me what to do," Kageyama protests as he begins to follow Hinata's instructions.

After Kageyama is done jotting down the temperatures of the respective liquids, Hinata takes the beaker with room-temperature water and pours it into the calorimeter. “Alright, Kageyama. Time for enthalpy.” Kageyama nods solemnly and Hinata takes the beaker with hot water and pours it into the calorimeter as well, screwing on the top afterwards and sticking in the thermometer to measure the end temperature.

“The temperature stopped going up,” Hinata notes after a few minutes, scribbling down the number.

The two take their seats at the desk and get out their notebooks to do the calculations on the change of heat. Natsu comes over to watch. “What are you guys doing?”

“Calculating enthalpy,” Hinata answers, staring down hard at the mostly blank paper apart from the information they’d recorded. “Kageyama,” He says seriously, “...do you remember the equation.”

Kageyama is staring hard at his paper as well. He slams his head on the table.

“Equation for what?” Natsu asks, moving around the two boys and feeling a little bored. 

“What’s ‘enthrapy’?”

“Enthalpy,” Kageyama corrects. “It measures the change in heat in a body.”

Hinata waves his hand. “Never mind that. We can get back to the equations later.”

“Ok. What kind of reaction was this then?”

“I-I said no math!!!!” Hinata shakes his head, eyes wide.

“No, stupid. I mean was it endothermic or exothermic?”

“U-um...both?”

Kageyama pinches the bridge of his nose and shakes his head. “Take notes.” Hinata scrambles for his pencil and holds it over his paper. “Hess’ Law states that the sum of the heats in a reaction is equal to the overall reaction. So when I ask what kind of reaction we had in our experiment, I’m asking about what happened to the heat, and vice versa. Got it?”  
Hinata jots a few notes down and nods in affirmation. Natsu just stares as she is unable to process any of what she just heard.

“So then we have exothermic and endothermic reactions, -thermic referring to heat. An exothermic reaction is one that releases heat; when this happens, the temperature rises and the enthalpy is negative. In turn, an endothermic reaction absorbs heat, meaning the temperature goes down and the enthalpy is positive.”

“Right!” Hinata yells. “The temperature went up when we added hot water, so it was exothermic, right?”

“Took you long enough, idiot.” Hinata scrunches his face at Kageyama. “So what we need to do now is math. The equation for this is delta H, or q, equals mass times specific heat capacity times delta temperature.” Kageyama writes this down to show Hinata as the redhead grimaces, because math is painful.

“What we want to figure out, in this case, is to what extent the hot water caused a change in heat for the colder water. Basically, we just plug in our measurements. The mass of the hot water after we’ve subtracted the beaker’s mass, the specific heat capacity of the first substance to go into the calorimeter, the room-temperature water, and then the initial temperature subtracted from the final temperature.”

“You guys are boring!!!” Natsu yells. “I’m going to go color.” And like that she’s out the door and gone. Hinata snorts.

The redhead follows Kageyama’s explanation and writes up the calculations. “How does this look, Kageyama?”

Kageyama looks over and blanches. “Did you hear a word of what I said? That’s all wrong, dumbass!” The coast is clear and child-free for cursing. 

“Oi, don’t get snarky! I did what you said–mass times heat capacity times temperature!” 

“No, no, I said times delta temperature, idiot!” Kageyama smacks Hinata’s head.

“Gah, that hurts, stupid Kageyama!” Hinata rubs the spot where the setter hit him, though the hurt had already gone. 

Kageyama takes the opportunity to pick up the pencil and rewrite the calculation. “There. Now it’s right.”

Hinata leans over to verify, “…are you sure?”

“Yep,” Kageyama ensures, closing his eyes smugly. 

“I feel like it’s still not right.” Hinata raises an eyebrow at the jumble of numbers, comparing them to their recorded observations. 

“Tch, what, are you doubting me? I double-checked, of course it’s right. I think.”

“Ok, I guess. I barely understand any of this, you may be stupid but you probably know more chemistry than me.” 

Kageyama starts but chokes back his retort and instead shrugs, “We should be fine.” Hinata beams at him, clearly amused. The two finalize their lab report. 

The two are cleaning up their equipment when Hinata shakes his head and grins, thinking about Natsu. “Poor kid, she has no idea what’s coming for her.” Kageyama grunts, drying the calorimeter. Hinata watches him and absent-mindedly leans onto his desk. There’s a crash. 

The boys’ eyes widen in tandem.

Kageyama’s voice sounds throughout the house, “Dumbass! You broke the beakers, I can’t believe you broke the beakers!” Screams echo.

~

Hinata wanted to pay for the broken beakers himself, but Kageyama begrudgingly insisted on pitching in. Sure, Hinata was a dumbass, but Kageyama was a good friend. 

The two had forgotten about the whole ordeal until during lunchtime, they were called to their chemistry teacher’s classroom. The boys made their way over together.

“What do you think this is about, Kageyama? Oh, oh, what if we’re getting congratulated on our lab report? We did a pretty great job. What if they want to give us a prize? Are we scientific geniuses?” Hinata has a bounce to his step as usual, walking backwards ahead of Kageyama and gesturing wildly. 

Kageyama keeps his hands in his pockets and blows a clump of hair obscuring his vision from his eye. “Oi, watch where you’re going before you trip yourself, you idiot. Beats me. Getting called by your teacher isn’t usually a good thing.”

Hinata frowns and faces forward by Kageyama’s side. “Ah, I’m sure we’ll be fine.” He bumps his shoulder to Kageyama’s arm. 

The pair walks into the chemistry classroom. 

“Ah, hello Kageyama, Hinata. Good of you to join me,” The teacher greets and the boys murmur greetings in return. “Please, come sit by my desk.” Once the two students settle across from the teacher, she begins. “I wanted to speak to you two about the lab report you turned in.”

Kageyama and Hinata exchange a look, and then nod at the teacher.

“…You failed.”

“WAH???” The two react in unison, eyes wide, jaws on the floor. 

The teacher continues, “This…means you won’t be able to go compete in Tokyo.”

“W-wait a minute!” Hinata springs out of his chair, “We thought we did really well, what happened?” Kageyama is frozen and ashamed, looking down at the ground sullenly.

“Well, you seem to have a grasp on the concepts, but the math was all wrong.” The teacher leafs through the pages of the report. 

Kageyama flinches and feels Hinata’s eyes on him. He had done a majority of the math and assured it was all correct. Clearly, he had been very, very wrong. 

“Is there anything we can do? Can we redraft the lab report? Some extra credit? We’ll clean your classroom for you every day for a month! Please, we’ll do anything!” Hinata’s voice squeaks. 

The teacher sighs. “I can’t let you redo the lab report. I wish I could, but the grades are already locked in the grading system. You can do some extra credit, but it won’t bring your grades up enough to allow you to travel. I’m sorry.” 

The two boys get up, understanding the meeting to be over. “Thank you, Miss.” 

Walking to the court, Hinata rubs his face. “Gaaaaah, how are we supposed to tell Daichi?” He stops in his tracks. “Suga will be so, so disappointed in us.” Kageyama shivers. Their steps drag on the ground and the walk is laden with fear and anxiety.

Upon arrival, Hinata stops by the door, feeling like stone. Goosebumps travel down his arms and legs. Kageyama slips right in without a pause. Hinata opens his mouth, but thinks better of it and steps in after Kageyama.

“Hey, Kageyama, Hinata!” Suga calls out and waves. Daichi is next to him, and Nishinoya, Tanaka, Tsukishima and Yamaguchi are there as well. 

Hinata feels sick, like he’s about to give a presentation he’s completely unprepared for. Nishinoya and Tanaka are already raving to each other about the tournament that’s only two weeks away, excited to crush to Aobajohsai. Tsukishima and Yamaguchi are hanging out in the corner, and yikes Suga and Daichi are walking towards Hinata. 

“Hey, Suga!” Hinata attempts to maintain control over his voice and fails. Suga smiles and raises an eyebrow at the high-pitched tone. Kageyama, who had been settling his things and getting ready, comes over. “How are my first-years doing? Excited for Tokyo?” Ah. Straight to the point, huh. Kageyama is weirdly calm. Maybe he’s accepted his fate. Worst of all, Daichi decides now is a great time to join the conversation. 

“Ah, yeah well, we’re – uh, we…” Hinata looks at Suga’s face. At Daichi. Then up at the ceiling. Then at his shoes. 

Kageyama clears his throat, grits his teeth, hands in fists at his sides, “We failed our chemistry project.”

Suga brings his hands to his hips. Daichi’s eyebrows raise in alarm and he crosses his arms.

Hinata can’t help it. The pressure is too great. The guilt, enormous. He failed his teammates, his captain, his coach. “Suga, we’re not going to Tokyo.” Hinata turns to Daichi and bows his head, “I’m sorry, Daichi, please give us any punishment you see fit!!!”

Kageyama repeats Hinata’s apology and bows his head as well. His cheeks are slightly red.

The two older boys blink. Suga gapes. Nishinoya and Tanaka at this point have stopped their conversation to overhear and are snickering to themselves. 

Hinata immediately regrets it when he next makes eye contact with Daichi. Kageyama starts when he notices as well. Daichi has his signature Scary Look in his eyes. The captain puts each hand on a shoulder of the two first-years. “What did I tell you about getting good grades?” Oh no. Here comes the stern talk. “We work hard in school so we can travel and play in tournaments.”

“Daichi, we know, we worked so hard on our project, we swear!” Hinata whines.

Kageyama nods in affirmation, “We really thought we had it.”

“Plus, it was Kageyama’s fault! He thought he understood the math but didn’t know it all!”

“Oi, don’t blame me, dumbass, you were a lost cause that would’ve brought our grade down more– “ Daichi’s Scary Look is back and the two shut up. Daichi continues his lecture and ultimately decides that the duo gets no quick training while the team is gone. 

“God has forsaken us,” Hinata declares gravely, eyes unfocused. What is left in life if there is no quick training? Kageyama is stone and Hinata waves a hand in front of his face. No reaction. 

Seeing that Daichi’s lecture is over, Suga comes over. Hinata is perplexed by the small smile on Suga’s face and–Suga hits the two over the head.

“Ow!” The two first-years exclaim in unison.

Nishinoya and Tanaka burst out laughing. “Maybe you should’ve tried getting a better grade.” Tanaka challenges, clearly pleased with himself. Nishinoya’s face is smug. 

Daichi’s voice comes from behind the second-years. “Tanaka, Nishinoya. You get extra training for that. …You didn’t do much better either. You barely passed your exams by the skin of your teeth.” 

“GAH???” 

Hinata laughs, but then remembers he doesn’t get to train his beloved move. “Daichi, PLEASE let us train while you’re gone?” 

“No.”

“Please?”

“No. Let’s start practice.”

Hinata’s pleads last late into the night.

**Author's Note:**

> Credit is due to my two friends Fe and Cami who gave me ideas for how Daich and Suga would react to the situation!
> 
> Chemistry sources:
> 
> http://chemistry.about.com/od/chemistryglossary/a/energydef.htm  
> http://www.physicsclassroom.com/class/thermalP/Lesson-1/What-is-Heat  
> https://chemistry.osu.edu/~woodward/ch121/ch5_work.htm  
> http://www.chemistryexplained.com/St-Te/Temperature.html  
> http://chemwiki.ucdavis.edu/Physical_Chemistry/Equilibria/Le_Chatelier%27s_Principle/Effect_Of_Temperature_On_Equilibrium_Composition/Exothermic_Versus_Endothermic_And_K  
> http://chemwiki.ucdavis.edu/Physical_Chemistry/Thermodynamics/Thermodynamic_Cycles/Hess%27s_Law


End file.
